Gas Fitter Practice Test

The instrument used to determine potential difference in an electrical circuit is the:

1. Voltmeter

2. Ohmmeter

3. Ammeter

4. Potentiometer

The correct answer is: Voltmeter

The instrument used to determine potential difference, commonly referred to as voltage, in an electrical circuit is a voltmeter. This device is specifically designed to measure the electrical potential difference between two points in a circuit. It is connected in parallel with the component whose voltage is being measured, allowing it to provide a direct reading of the voltage present. A voltmeter typically has a high resistance to ensure that it does not significantly alter the circuit's operation while measuring voltage. This characteristic is crucial because it minimizes the impact of the measurement on the circuit's performance, leading to accurate readings. Understanding the functions of other instruments highlights the specialized purpose of the voltmeter. An ohmmeter measures resistance, an ammeter measures current, and a potentiometer can measure both voltage and resistance but is generally used for more specialized applications, such as calibrating other instruments or in experimental settings. Each of these instruments serves distinct purposes within the realm of electrical measurements, but the voltmeter is uniquely suited for measuring potential difference.